Plastic pipe bending jig

ABSTRACT

A plastic pipe bending jig for establishing bend curvature and configuration having a plurality of operatively interconnected arms, pipe receiving clamps connected to the radial extremities of such arms, such clamps being radially and angularly adjustable to the desired radius and angle of curvature for the pipe, and indicia associated with the jig for determining such radial and angular displacement of the clamps. The jig is used by adjusting the clamps to define the desired pipe configuration, heating the pipe until pliable and placing the same in the clamps until hardened.

United States Patent 1 Curtis et al.

1 PLASTIC PIPE BENDING JIG [76] Inventors: John S. Curtis, 3659 CummingsRd., Cleveland Heights, Ohio 44118; Lee A. Miller, 15104 Hill Dr.,Novelty, Ohio 44072 [22] Filed: May 19, 1971 [21] Appl. No.: 144,817

52 US. Cl 269/81, 65/281, 269/45,

269/104, 269/152, 425/392 51 Int. (:1. B29g 7/00, B23q 3/06 58 Field ofSearch 269/37, 45, 97, 104,

[ 1 Dec.4,1973

Primary ExaminerRobert L. Spruill Attrney-Oberlin, Maky, Donnelly &Renner 57 ABSTRACT A plastic pipe bending jig for establishing bendcurvature and configuration having a plurality of operativelyinterconnected arms, pipe receiving clamps connected to the radialextremities of such arms, such clamps being radially and angularlyadjustable to the desired radius and angle of curvature for the pipe,and indicia associated with the jig for determining such radial andangular displacement of the clamps. The jig is [56] References CitedUNITED STATES PATENTS used by adjusting the clamps to define the desiredpipe configuration, heating the pipe until pliable and plac- 2 g theSame in the clamps until hardened. 2,936,803 5/1960 Jorick 269/45Claims, 9 Drawing Figures 43 in 'l- P 1 l 1 1], 1H1 H1 1 4o l 1 l t,

46 2| I P e PATENTEB DEC 4 I373 WEI 1 BF 2 INVENTOPS 5. CURT/S LEE A.M/LLER JOHN ATTORNEYS PLASTIC PIPE BENDING JIG The present inventionrelates as indicated to a plastic pipe bending jig and more particularlyto a jig which may be used with pipes of varying diameter to produce anygiven curvature or configuration in such pipe.

Field bending of plastic pipe to given configurations is primarilyaccomplished by one of two methods, namely, the use of large templatesor line of sight judgment. Both of such methods have disadvantages whichmitigate against their successful use in field applications.

The templates in order to be adaptable to as many bending operations aspossible have a plurality of lines scored on the faces thereof to act asguides in the bending of the plastic pipe. The use of such a largenumber of guidelines necessarily requires extensive surface area toaccommodate the same. Thus, the template is normally of relatively largesize whereby it may not be readily transported or stored. Additionally,no matter how many guidelines are proliferated on the surface of thetemplate, it isimpossible to provide for every possible curvature orconfiguration that may be desired. Therefore, when an appropriateguideline is not found on the template, it is necessary to bend the piperelying upon line of sight judgment which suffers from the disadvantagesdiscussed immediately hereinafter.

The primary disadvantage of bending plastic pipe using only line ofsight judgment is the lack of bend accuracy. Without such accuracy, thebend radius, the segment of circle described by the bend, and therelative horizontal and vertical positioning of the pipe sectionstangentially connected to the extremities of the curve cannot becontrolled or readily determined which results in problems of fieldassembly. If the dimensional variances are too great, it may require therebending of such pipe or the use of another pipe bent to the desiredconfiguration.

Accordingly, it is the primary object of the present invention toprovide a pipe jig which can be used to bend plastic pipe of variousdiameters accurately.

It is another important object of the present invention to provide aplastic pipe bending jig which is adjustable so as to form the curvatureand configuration of bends having various radii and number of degrees ofturn in the curve segment.

It is another important object of the present invention to provide apipe bending jig which may be arranged to bend pipe to given irregularconfigurations.

Another object of the present invention is to provide a structurallystrong and accurate pipe jig which is lightweight for easy transportthereof and relatively small in size for easy storage.

Other objects and advantages of the present invention will becomeapparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention,then, comprises the features hereinafter fully described andparticularly pointed out in the claims, the following description andthe annexed drawings setting forth in detail certain illustrativeembodiments of the invention, these being indicative,

however, of but a few of the various ways in which the principle of theinvention may be employed.

In the drawings:

FIG. 1 is a top plan showing one form of the pipe bending jig, with thepipe bent thereby shown in phantom;

FIG. 2 is a front elevation of the pipe jig of FIG. I as indicated byline 2-2 in the latter;

FIG. 3 is a top plan of another embodiment of a plastic pipe bending jigaccording to the present invention; with the pipe bent thereby and anadditional arm with a center pipe clamp shown in phantom;

FIG. 4 is a front elevation of the pipe jig of FIG. 3 as indicated byline 4-4 in the latter;

FIG. 5 is a bottom plan of a modification of the outer clamp assemblyconstruction shown in FIG. 3;

FIG. 5A is a schematic top plan of the embodiment of FIG. 3 having themodified outer clamp assembly of FIG. 5 thereon, with the pipeillustrated;

FIG. 6 is a top plan of still another embodiment of the pipe jigaccording to the present invention, with the pipe bent thereby shown inphantom;

FIG. 7 is a front elevation of the pipe jig of FIG. 6 as indicated byline 7-7 in the latter; and

FIG. 8 is an enlarged verticalcross section of the telescoping arms ofFIG. 6, taken along the plane of line 88 in FIG. 6.

Referring now in more detail to the drawings and initially to FIGS. 1and 2, a plastic pipe bending jig, indicated geneally at l, isillustrated which includes a base member 10, an arm bracket 20, two arms30 and 31 and two clamps 40 and 41. For purposes of illustration, thepipe 50 shown in phantom is bent so as to form a 45 elbow, however, itwill be clear as the following description proceeds that a wide range ofelbow angularities and radii of curvature is possible with the jig ofthe present invention.

The base plate or member 10 is a relatively thin quadrant having aprotractor 11 etched or die scored thereon adjacent arcuate surface 12.Although the protractor shown is of only in extent with 5 increments, itis obvious that if more accuracy were desired, a greater number ofincrements could be used, or if a greater range was desired, adifferently shaped base member with, for example, a protractor etchedthereon could be used. The base plate has an aperture therein throughwhich an upwardly extending stud 13 is disposed, such stud being affixedto the bottom surface of the base plate 10 as shown in FIG. 2. One sideof the plate 10 has a plurality of upstanding and rebent tabs 14 forreceiving arm 31 therein, such arm being radially slidably adjustable,the tabs 14 providing sufficient frictional resistance to assist inmaintaining the arm in its position of adjustment.

Arm bracket 20 is an integrally formed plate having an essentiallysemi-circular projecting shoulder 21 and an elongated rectangularsection 22. The shoulder 21 has a centrally located aperture which isadapted to receive stud 13, with the bottom surface of such shoulderbearing against the upper surface of arm 31. The lateral edges ofelongated rectangular section 22 are provided with a plurality ofupstanding and rebent tabs 24, similar to the tabs 14, for receiving arm30. Also, one edge of such section 22 is provided with an outwardlyextending angle indication projection 25. The edge 26 of projection 25is laterally offset from the edge of section 22 an amount which is equalto the distance that the center of aperture 23 is offset from the sameedge in order to give an accurate indication of angularity about thepivot point of the arm bracket.

Arm is horizontally received in tabs 24 for lineal radial slidingmovement therein as described above in connection with arm 31. The armsare each of substantially equivalent length with indicia marks 32 ofcorresponding scale and position etched or die scored on their topsurface. As in the case of the protrator, the number of marks useddepends upon the accuracy desired and the range of the scale. The radialposition of the arms may thus be readily determined by reading thenumber associated with the indicia mark which is in registry with orclosest to the edge of the protractor 12, which edge is of known radius.

The radial extremities of arms 30 and 31 are perpendicularly bent withrespect to the rest of the arm as at 33 and 34, respectively, to presentan external face to which clamps and 41 defining straight elongatedguides are welded or otherwise suitably connected. Such clamps arepositioned so that their pipe supporting surfaces will be disposed inthe same horizontal plane. This requires that the clamp 40 be placedrelatively lower on the external face of portion 33 than clamp 41 isplaced on the external face of 34 since arms 30 and 31 are slightlyvertically offset, as best shown in FIG. 2. In addition, the clamps arepositioned so that the opposed inner edges 42 and 43 thereof establishthe points where the curve begins and the clamping section defines atangent to such curve.

Since clamps 40 and 41 are identically constructed, only clamp 40 willbe described in detail. Such clamp includes a generally U-shape hollowframe section having inner wall 44, outer wall and bottom pipesupporting wall 46. Disposed between walls 44 and 45 is a verticallyoriented, laterally adjustable pressure plate 47 which bears against theouter surface of the pipe inserted in the clamp. Such pressure plate islaterally adjusted in a well known manner by swivel bolt 48 which at itsend is operatively connected to such plate and at an intermediateportion is threaded through nut 49, the bore of which is in alignmentwith an aperture in wall 45. Thus, by adjusting the lateral position ofthe pressure plate 47, plastic pipes of varying diameter may be receivedin the clamp.

The above described jig device is set up for bending a plastic pipe to agiven angular extent of curvature and radius in the following manner.Initially, each arm is radially adjusted until corresponding marks 32 oneach arm in registry with a common reference point such as the edge ofthe protractor. Secondly, the arm bracket 20 and thus arm 30 connectedthereto are pivoted about stud 12 until edge 26 is in alignment with theindicia for the given angle. Finally, wing nut 28 is drawn downwardlyuntil the bottom surface thereof bears against the top surface offriction washer 29 which in turn bears against arm 31 and shoulder 21,the latter bearing against arm 31, thereby locking the bracket and armsin the desired position. The washer may be rigid and stepped or flexibleproperly to bear against the subjacent surfaces.

The pressure plates are then adjusted to provide the correct spacing toaccept the pipe. After the jig is set up in the manner defined above,the pipe 50 is heated until it becomes pliable and can be bent forinsertion into clamps 40 and 41. The pipe is allowed to cool while thusheld until it hardens. The cooling may be accelerated by sponging orspraying with water. The pipe thus bent is then removed.

For certain pipe or tube sizes, the walls may tend to buckle or collapseif the curvature is too severe. This can usually be avoided by pluggingthe pipe ends, as indicated at P, prior to heating. Sufficient airpressure is built up inside the pipe during the heating thereof topreclude such buckling.

Although the above-described use of the jig for bending pipe wasspecifically directed to the device of FIGS. 1 and 2, the same generalsteps are followed in using the other jig embodiments set forthhereinafter. The particular manner of adjusting radius and extent ofcurvature should become clear from the structural description of suchother forms of the device. Therefore, an operational or methoddefinition as given above will not be repeated for every alternativemodification discussed.

Referring now to FIGS. 3 and 4, a second embodi ment of the presentinvention is shown having an arcuate base member 120 and arms 130, 131and 132. The base member 120 comprises an open ended, hollow rectangularframe section having the top surface thereof provided with twoelongated, parallel, arcuate slots commonly designated at 121 whichdefine between the ends thereof an arc of The top surface of member hasetched or die scored thereon radially directed marks 122 having anumerical scale associated therewith to indicate angularity of arms 130,131 and 132.

Such arms are each provided with both elongated longitudinal slotscommonly designated 133 and transverse indicia markings 134. Bolts 135pass through the portions of slots 133 and 121 which are in alignment,such bolts having nuts 136 threaded thereon to attach the arms to thebase member. When the nuts are tightly drawn against such base member,it is obvious that the angular and radial position of the arms arefixed. However, when the nut is not tightly drawn up to the base member,the arms 130, 131 and 132 may be both angularly and radially adjusted tothe extent of slots 121 and 133, respectively.

Arms 131 and 132 have clamps 140 and 141 welded or otherwise suitablyconnected to the radial extremities thereof, such clamps being of thesame construction as that previously discussed. Arm 130 has a guideassembly at the radial extremity thereof to aid in the formation of asmooth elbow curve. As illustrated, the guide assembly comprises adownwardly extending cylindrical member 145 which is adaptedtangentially to engage the radially inner wall of the plastic pipe. Asimilar guide assembly or assemblies may be provided in the otherillustrated embodiments.

However, if it is desired to maintain a slight clamping pressure at suchintermediate point to substantially ensure that the bend will bemaintained in the same horizontal plane, a clamping assembly asillustrated in phantom at 146 may be provided. Such a clamping assemblywould be similar to the clamps described hereinabove, but rather thanhaving a transversely moving pressure plate it has a cylindricallyformed transversely moving pressure member 147. The cylindrical shape ofmembers 145 and 147 allow either guidance or pressure application to thepipe 150 without interrupting curvature regularity since such pipe iscontacted only at points of tangency to the arc.

By having an arcuate base member, it is possible to describe a largerradius of bend curvature with shorter arms than is possible if such armsare pivoted about the actual center point. Thus in the most commonlyused radii for plastic pipe bends or elbows of from 12 to 48 inches, therespective arms need be only slightly longer than three feet with a basemember radius of approximately a foot.

The shorter arms in conjunction with support radially outwardly of thecenter point reduces flexure in the arm members so that there will bevery little vertical variance as between the respective clamp members.It is also apparent that if smaller radii bends were desired, one maydisconnect the respective arms from the base member, reverse the same byrotating the arm through 180arc and reconnect the arms to the basemember. Inverting the arms or substituting one for the other will enablethe clamps to hold the linear plastic pipe tangentially to theextremities of the curved segment.

Referring now to FIG. 5, a modified, pivotable clamp assembly 140A to beused in conjunction with the pipe jig of FIGS. 3 and 4 is illustratedhaving the previously described clamp 140 on the underside and pivotallymounted to the bottom surface of quadrant 142A integrally formed withthe arm 132A. The quadrant has a protractor etched or die scored uponthe upper surface thereof adjacent arcuate surface 143A, whereby theangularity of the clamp 140A may be determined by reading the angleindicated by the numerical indicia associated with the marking inalignment with inside surface 144A of the clamp. The wing nut 145Adisposed on top of quadrant 142A on the connective stud allows the clampto be pivoted when loose and locks the clamp in a given angular positionwhen tight.

As best shown in FIG. 5A, the pivotability of the clamp members allowsthe plastic pipe to be formed into more complex configurations, such asthe reverse curve illustrated. In the schematic, clamps 140A and 141Aare linearly aligned by rotation of such clamps through an angle of 45.Depending upon the vertical height desired for the apex of the U-shapebend, the radial position of arm 130 is set accordingly. Theconfiguration defined by the three clamp members 140A, 141A and 146 thusvaries from the simple 90 elbow shown in FIG. 3. As is readily apparentfrom the schematic view, any number of configurations is possibledepending upon the radial and angular positioning of the three arms andclamps. Further pipe configurations are possible by adding a greaterdegree of angular freedom for both the arms and clamps as well as byadding a greater number of arms.

Pivotal clamp assemblies may also be employed upon arms 30 and 31 inFIG. 1. This would allow the operator of the jig to form plastic pipesinto configurations other than elbows.

Referring now to FIGS. 6, 7 and 8, a third embodiment of the presentinvention is illustrated which has two linearly telescoping arms 230 and231 having clamp assemblies 240 and 241 pivotally connected to theradial extremities thereof. The arm 230 is of hollow rectangularconstruction as shown in FIGS. 7 and 8 and is provided with at least onedetent 232 in the top surface thereof. Such detent receptivelycooperates with vertical holes 233 in arm 231, such holes beinglongitudinally equally spaced in convenient dimensional increments. Whenthe detent is received in a hole 233 as shown in FIG. 8, the arms arelocked against further linear movement, unless a releasing force isapplied thereto. The relative linear displacement between the twoclamping assemblies is indicated by transversely extending indicia marks234 on arm 231, which are read when they are in alignment with the endsurface 235 of arm 230.

Although the telescoping arms are illustrated as being rectangular incross-section, it is obvious that other structural forms could also besuitable employed. For example, the arms could be tubular or for thatmatter of flat bar stock. Additionally, other forms of locking the armsin a fixed telescopic relationship could be used. For example, in thepresent construction, locking screws disposed in longitudinally spacedholes in arm 230 could be used with such locking screws being adapted tobear against the surface of arm 231 when tightened to lock the same inits linear position.

Moreover, the concept of two arms confined to relative linear movementwith pivotal clamps attached to the radial extremities thereof could beaccomplished by methods other than the telescopic relationshippreviously discussed. For example, a turnbuckle could be employedbetween the two arms to vary the radial positioning of the same.

Each of the clamp assemblies 240 and 241 comprise a fan-shaped member242 having a clamp 243 welded or otherwise suitably connected to the topsurface thereof. The fan-shaped base member has upwardly extending stud244 welded thereto, such stud in the assembled condition of the jigpassing through an aperture 236 in the radial extremities of the arms. Awing nut 245 is threadably received on stud 244 to lock the clampassembly 240 in a fixed position when tightly drawn down upon the armwith which it is associated or to allow pivotal movement of suchclamping assembly when loosely associated with such arm.

The top surface of fan-shape member 242 has a protractor scale 246etched or die-scored thereupon adjacent the arcuate surface 247. Theangular position of the clamp is determined by reading the numericalfigure associated with the line in alignment with the side edge of thearm 230. As shown by the phantom lines in FIG. 6, when the clampassemblies are pivoted so that the clamp 243 is inclined at a 45 anglewith respect to the arms, a bend is formed in the plastic pipe receivedby such clamps.

It is obvious that other methods may be employed to vary the relativeradial and angular positioning of the pipe receiving and holding clamps.For example, a three bar triangular linkage with clamps connected to thepivotal intersections thereof could be employed which wouldsimultaneously vary the radial and angular positioning of such clamps.

Other modes of applying the principle of the invention may be employed,change being made as regards the details described, provided thefeatures stated in any of the following claims, or the equivalent ofsuch be employed.

The embodiments of the invention in which an exclu-- sive property orprivilege is claimed are defined as follows:

1. A jig positionable on a flat support surface to facilitate thebending of heat softenable plastic pipe to a given curvature over acurved section heated to the softening temperature of said pipe andhaving curved section ends comprising interconnected spaced-apartstraight elongated guides positionable on said support surface to holdsaid pipe at and beyond said curved section ends with said curvedsection supported on said support surface between said guides until saidcurved section cools to the hardening temperature of said pipe so thatsaid guides establish tangential straight segments of said pipe beyondsaid curved section ends with said straight segments being tangent tosaid curved section at said curved section ends, a pair of elongatedsupport arms having outer arm ends, said arms being attached to supportmeans, said guides being attached to said outer arm ends, radialadjustment means for radially adjusting said arms relative to saidsupport means, at least one of said arms being angularly adjustablerelative to said support means for angular movement toward and away fromthe other of said arms, and at least one of said guides attached to oneof said arm ends being angularly adjustable about a substantiallyvertical axis relative to said one arm end.

2. The jig of claim 1 wherein said guides include inner and outer walls,said inner walls being adjustably movable relative to said arm ends andtoward and away from said inner walls to vary the space therebetween foraccommodating pipe of varying diameters, said inner walls being fixedrelative to said arm ends so that said inner walls maintainpredetermined radii from said radial adjustment means regardless of theradial adjusted position of said arms and regardless of the adjustedposition of said outer walls.

3. A jig to facilitate the bending of plastic pipe to a given curvaturecomprising straight elongated guides to hold said pipe beyond the endsof such curvature to establish tangential straight segments of the pipeat the extremities of such given curvature, support meansinterconnecting said guides, said support means including means to varythe angular relationship between said guides, said support meansincluding at least two arms operatively interconnected having saidguides connected to the outer extremities thereof, said support meansfurther including a base member to which said arms are connected, saidbase member being in the form of a protractor, and indicia means thereonto measure the angle between said arms.

4. The jig as set forth in claim 3 including indicia means on said armsto measure the radial position of said arms with respect to said base.

5. A jig to facilitate the bending of plastic pipe to a given curvaturecomprising straight elongated guides to hold said pipe beyond the endsof such curvature to establish tangential straight segments of the pipeat the extremeties of such given curvature, support meansinterconnecting said guides, said support means including means to varythe angular relationship between said guides, said support meansincluding at least two arms operatively interconnected having saidguides connected to the outer extremities thereof, said support meansfurther including a base member to which said arms are connected, one ofsaid arms being connected to said base member to have only a radialdegree of freedom, and the other of said arms being connected to saidbase member to have both angular and radial degrees of freedom.

6. A jig as set forth in claim 5 wherein said base member comprisesfolded tabs to receive said one arm, and a plate superimposed upon andpivoted to said base member, said plate having folded tabs to receivesaid other arm.

7. A jig as set forth in claim 6 including a stud pivotally joining saidbase and plate having a nut thereon which when drawn down locks saidplate, other arm and one arm against movement.

8. A jig as set forth in claim 7 including means beneath said nutproperly to distribute the force thereof to subjacent surfaces.

9. A jig to facilitate the bending of plastic pipe to a given curvaturecomprising straight elongated guides to hold said pipe beyond the endsof such curvature to establish tangential straight segments of the pipeat the extremities of such given curvature, support meansinterconnecting said guides, said support means including means to varythe angular relationship between said guides, said support meansincluding at least two arms operatively interconnected having saidguides connected to the outer extremities thereof, said arms having aslot along the major axis thereof, an arcuate base member having atleast one arcuate slot therein, said arms being joined to said basemember by connection means disposed within said arm and base memberslots at their points of intersection.

10. A jig as set forth in claim 9 including a radially and angularlyadjustable third arm connected to said base member, said third armhaving a pipe bend guide on the outer end therof.

1. A jig positionable on a flat support surface to facilitate thebending of heat softenable plastic pipe to a given curvature over acurved section heated to the softening temperature of said pipe andhaving curved section ends comprising interconnected spaced-apartstraight elongated guides positionable on said support surface to holdsaid pipe at and beyond said curved section ends with said curvedsection supported on said support surface between said guides until saidcurved section cools to the hardening temperature of said pipe so thatsaid guides establish tangential straight segments of said pipe beyondsaid curved section ends with said straight segments being tangent tosaid curved section at said curved section ends, a pair of elongatedsupport arms having outer arm ends, said arms being attached to supportmeans, said guides being attached to said outer arm ends, radialadjustment means for radially adjusting said arms relative to saidsupport means, at least one of said arms being angularly adjustablerelative to said support means for angular movement toward and away fromthe other of said arms, and at least one of said guides attached to oneof said arm ends being angularly adjustable about a substantiallyvertical axis relative to said one arm end.
 2. The jig of claim 1wherein said guides include inner and outer walls, said inner wallsbeing adjustably movable relative to said arm ends and toward and awayfrom said inner walls to vary the space therebetween for accommodatingpipe of varying diameters, said inner walls being fixed relative to saidarm ends so that said inner walls maintain predetermined radii from saidradial adjustment means regardless of the radial adjusted position ofsaid arms and regardless of the adjusted position of said outer walls.3. A jig to facilitate the bending of plastic pipe to a given curvaturecomprising straight elongated guides to hold said pipe beyond the endsof such curvature to establish tangential straight segments of the pipeat the extremities of such given curvature, support meansinterconnecting said guides, said support means including means to varythe angular relationship between said guides, said support meansincluding at least two arms operatively interconnected having saidguides connected to the outer extremities thereof, said support meansfurther including a base member to which said arms are connected, saidbase member being in the form of a protractor, and indicia means thereonto measure the angle between said arms.
 4. The jig as set forth in claim3 including indicia means on said arms to measure the radial position ofsaid arms with respect to said base.
 5. A jig to facilitate the bendingof plastic pipe to a given curvature comprising straight elongatedguides to hold said pipe beyond the ends of such curvature to establishtangential straight segments of the pipe at the extremeties of suchgiven curvature, support means interconnecting said guides, said supportmeans including means to vary the angular relationship between saidguides, said support means including at least two arms operativelyinterconnected having said guides connected to the outer extremitiesthereof, said support means further including a base member to whichsaid arms are connected, one of said arms being connected to said basemember to have only a radial degree of freedom, and the other of saidarms being connected to said base member to have both angular and radialdegrees of freedom.
 6. A jig as set forth in claim 5 wherein said basemember comprises folded tabs to receive said one arm, and a platesuperimposed upon and pivoted to said base member, said plate havingfolded tabs to receive said other arm.
 7. A jig as set forth in claim 6including a stud pivotally joining said base and plate having a nutthereon which when drawn down locks said plate, other arm and one armagainst movement.
 8. A jig as set forth in claim 7 including meansbeneath said nut properly to distribute the force thereof to subjacentsurfaces.
 9. A jig to facilitate the bending of plastic pipe to a givencurvature comprising straight elongated guides to hold said pipe beyondthe ends of such curvature to establish tangential straight segments ofthe pipe at the extremities of such given curvature, support meansinterconnecting said guides, said support means including means to varythe angular relationship between said guides, said support meansincluding at least two arms operatively interconnected having saidguides connected to the outer extremities thereof, said arms having aslot along the major axis thereof, an arcuate base member having atleast one arcuate slot therein, said arms being joined to said basemember by connection means disposed within said arm and base memberslots at their points of intersection.
 10. A jig as set forth in claim 9including a radially and angularly adjustable third arm connected tosaid base member, said third arm having a pipe bend guide on the outerend therof.